A conventional liquid level detector includes a float arm having a float floating on a liquid surface, an arm holder holding the float arm and having a rotational supporting point for the float arm, a frame bearing the rotational support point of the arm holder, a hard wiring board fixed to the frame, a contact holding member having a sliding contact sliding on the hard wiring board and fixed to the arm holder, and a terminal electrically connected to an electrode formed on the hard wiring board (refer to JP 2002-357473 A, for example).
However, the conventional liquid level detector is provided with a land for connecting the terminal to the hard wiring board made of ceramics. Because the land is necessary, the area of the hard wiring board cannot be reduced. In addition, the hard wiring board is formed by producing a plurality of circuit boards from a large board, but since the wiring board is large in area, it is impossible to manufacture many wiring boards from a large board, so that costs cannot be reduced.
The invention has been made in view of this problem and a main object of the invention is to provide an inexpensive and small-sized liquid level detector.